Timeout on RHEL subscription check (#12115)

subscription-manager status can in some circumstances just never
terminates, with nothing indicating the problem from the Ansible
playbook log.
This makes it difficult to find the hosts misbehaving.

Add a timeout to the subscription checks (defaulting to 3 minutes). This
should be more than enough for normal circumstances while allowing
easier troubleshooting, as the hosts will be FAILED instead of the
playbook just waiting indefinitely.